The twelfth annual record for indoor radiation control (1975)

This is the 12th annual record for the indoor radiation control in Research Reactor Institute, Kyoto University. The number of failures of monitors employed has been increasing gradually since several years ago because of their superannuation. However, since maintenance budget has not been increased these years, it will be obliged to perform the control works at the slight sacrifice of safety and the rate of operation. The record is divided into four parts, regular control inside the facility, regular control of the critical assembly building, radiation control of the linac and the items related to general management in the last section. On the former two regular controls, space dose rate, monthly cumulative dose, surface contamination density, concentrations of radioactivity in water, radioactive dust and gas, and the Management of monitors are reported in detail. On the linac, control equipments and a few experiences are described. In the general management section, evaluation of exposure dose in the surrounding of the site, periodical voluntary inspection and regular inspection, and abnormality records are reported, but no accident is recorded. (Wakatsuki, Y.)